DDR Extreme Monitor Flicker

Not sure if this is the right thread, but I thought I'd try here anyway.

I recently bought a DDR Extreme machine, and the monitor flickers like crazy. The colors and everything else are fine. I've tried degaussing the monitor, with limited success. No wires seem to be loose, either.

After a while (about half an hour), the monitor only flickers once or twice during a song, but it's still pretty irritating.

Has anyone else had this problem with an arcade monitor before? Does anyone know how to fix this?

Is there anything nearby that you think would cause electronic interference? Sometimes flickering issues occur when two machines running within the same frequencies are right next to each other. Arcade machine are usually shielded poorly, if at all.

There are a few computers and computer monitors nearby, but they're not plugged in. The only other thing in this room that's plugged in and running at the same time is the floor fan I have right next to the machine.

The screen flickered when I first checked out the machine at my dad's storage unit (where it was dropped off), and it still persists at its current location (my home).

Ah, all right. I'm not about to check that kind of thing out, but I'm glad that there is some sort of solution (so far tapping on the glass kinda fixes things, which makes me think something is loose, though my dad checked all kinds of connections and said they seemed fine).